PRELIMINARY ASSESSMENT

The proposed modernization plan is to make the building accessible, and reduce the seismic risk while preserving the historic character of the existing building. The deficient roof and shear walls will be structurally strengthened to better withstand a major earthquake. The recommended structural retrofit is to add plywood sheathing to the roof, sway bracing, roof-wall anchors, and steel trusses. The original ceiling and wall construction will be temporarily braced throughout.
Stairway, restrooms, staff room, electrical room, mechanical room will be modified or relocated to conform to accessibility requirements, life safety related code requirements and owner improvements.

New or alteration construction will meet State (Title 24) and Federal (Americans with Disabilities Act) guidelines. Given the historic significance of the building, a careful review will be made to determine the most appropriate disabled access modifications. The anticipated disabled access work includes: adding an elevator; reconfiguring existing restrooms and adding new restrooms; adding a new fire exit stair; new counters, revised layout; and modified doors.

Conformance with the latest life safety code requirements will include: providing a larger electrical room, larger mechanical room; wider fire exit stair; new accessible restrooms, and wider library aisles. Building code impacts involve the updating of the heating, ventilating, plumbing, fire protection, electrical and other building control systems.

Current law requires removal of asbestos-containing materials (ACMs), such as plasterboard walls, floor tiles, and roofing related to the seismic retrofit and disabled access work. The removal of ACMs will require relocation of the building occupants to eliminate health risks associated with exposure to airborne particles. Lead that is impacted will also have to be abated.

The recommended modernization plan includes a minimal expansion at the rear of the building to recoup space lost due to disabled access and seismic work. The branch is located at the bottom of a hill and the Main entrance is on the second level in the front of the building. Other work includes upgrading the HVAC system, updating data/electrical outlets, replacing flooring, improving lighting, replacing windows, refinishing wood surfaces, painting, and landscape restoration.

ASSESSMENT DETAIL

SEISMIC

The load path is deficient as follows:

There are no ties at the reentrant corners.

The roof diaphragm chords are overstressed in the north-south and east-west directions.

The floor diaphragm chords are overstressed in the north-south direction.

There is significant torsion because of the irregular shape of the building.

There are non-reinforced hollow clay tile partitions around the basement furnace room and corridor.